<!DOCTYPE html>
<html lang="en" ng-app="myModule">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <script src="js/angular-1.3.0.js"></script>
</head>
<body>
    <div ng-controller="myCtrl">
        <div>
            {{str}}
        </div>
        <div>
            <button ng-click="btn_click()">点我</button>
        </div>
    </div>
    <script type="text/javascript">
        var myModule = angular.module("myModule",[]);
        myModule.controller("myCtrl",["$scope",function($scope){
            $scope.str = "first string...";
            $scope.btn_click = function () {
              $scope.str = "second string...";
            };
        }]);
    </script>
</body>
</html>